Not Applicable.
The invention relates to concrete retaining wall blocks and to retaining walls constructed from such blocks.
Concrete blocks are frequently used for constructing retaining walls. Rectangular blocks have been stacked to form a retaining wall and then back filled on one side to form a terrace. The backfill can exert a sufficient force on the retaining wall blocks to cause the stacked blocks to move out of their original position. In some cases, the blocks are stacked to form a stepped wall so that the front face of each row or tier of blocks is offset slightly behind the front face of the adjacent lower row of blocks. Further, a raised lip has sometimes been formed along the upper edge of the block adjacent the front face to prevent the stepped blocks from sliding out of position, as shown in Arvai et al. U.S. Pat. No. 5,791,827. In order to eliminate this problem, retaining wall blocks have sometimes been formed with a groove extending along a bottom surface parallel to an exposed face of the block and a raised portion is formed on a top surface to extend parallel to the front face. The groove on a stacked block receives the raised portion on an adjacent lower block for maintaining alignment of the front faces of the stacked blocks. Such an arrangement is shown, for example, in Forlini U.S. Pat. No. 5,647,185. Retaining wall blocks also may be formed with round knobs on the top surface which fit into a groove on the bottom surface of a stacked block to permit forming a curved retaining wall, as shown in Wagenaar U.S. Pat. No. 5,337,527. Another method for stabilizing a retaining wall constructed from concrete blocks is through the use of a geogrid tie back system in which the retaining wall is secured to the ground behind the retaining wall with ground anchors. The use of ground anchors for stabilizing retaining walls is shown, for example, in Kelly, Jr. U.S. Pat. No. 5,402,609 and in Wagenaar U.S. Pat. No. 5,337,517.
The invention is directed to retaining wall blocks and to retaining walls formed from such blocks. The retaining wall is constructed from tiers of cast concrete blocks which are trapezoidal in plan and have rectangular front faces which are textured and, optionally, colored to simulate a desired type of stone or rock. The blocks are provided with at least one top projection or knob which is received by a bottom groove in a block in an adjacent upper tier for interlocking the tiers of blocks. Preferably, the bottom groove is omitted from the blocks in the lowermost tier.
The top projections are omitted from blocks used in the top row of blocks in the retaining wall. The top blocks may have an top surface portion which is recessed below an upper edge of the front face of the blocks to allow extending top soil or other material over the top surface portion up to the front face. In an alternate embodiment, the upper surface of the top blocks is recessed below upper edges of the front and rear to define a trough extending between the sides parallel to the front face. The troughs in a row of top blocks form a drain ditch which extends along the top of the retaining wall.
Planter blocks also may be used in one or more tiers below the uppermost tier. Each planter block has a trough in its upper surface which extends between the sides of the block parallel to and adjacent the front face of the block. The knobs on the top of the planter block are spaced further behind the front face than the bottom recess, so that the front face of blocks in an adjacent upper tier are spaced behind the front face of the planter block and at least a portion of the trough is exposed. The trough may be filled with soil and plants.
In a further embodiment, the blocks are provided with finished front and rear faces for constructing a free standing wall.
Accordingly, it is an object of the invention to provide retaining wall blocks and retaining walls constructed from such blocks.
Other objects and advantages of the invention will become apparent from the following detailed description of the invention and the accompanying drawings.
FIG. 1 is a perspective view as seen from the upper right front of a basic retaining wall block for constructing a retaining wall according to the invention;
FIG. 2 is a top plan view of the retaining wall block of FIG. 1;
FIG. 3 is a perspective view as seen from the upper right front of a top block for constructing a retaining wall according to one embodiment of the invention;
FIG. 4 is a right side elevational view of the top block of FIG. 3;
FIG. 5 is a perspective view as seen from the upper right front of an end top block for constructing a retaining wall according to a further embodiment of the invention;
FIG. 6 is a perspective view as seen from the upper right front of a drain ditch top block for constructing a retaining wall according to a further embodiment of the invention;
FIG. 7 is a right side elevational view of the top block of FIG. 6;
FIG. 8 is a perspective view as seen from the upper right front of a planter block for constructing a retaining wall according to a further embodiment of the invention;
FIG. 9 is a right side elevational view of the planter block of FIG. 8;
FIG. 10 is a cross sectional view through one embodiment of a seven tier retaining wall constructed with blocks according to the invention;
FIG. 11 is a cross sectional view through a further embodiment of a ten tier retaining wall constructed with blocks according to the invention, with four tiers of planter blocks and topped with a drain ditch block;
FIG. 12 is a fragmentary perspective view of a stepped retaining wall according to a further embodiment of the invention;
FIG. 13 is a fragmentary perspective view of a landscape area including two serpentine retaining walls according to the invention;
FIG. 14 is a perspective view of a top block for a free standing wall according to the invention;
FIG. 15 is a perspective view of a half top block for a free standing wall;
FIG. 16 is a perspective view of an intermediate tier block for a free standing wall according to the invention;
FIG. 17 is a perspective view of a half intermediate tier block for a free standing wall;
FIG. 18 is a perspective view of a lowermost tier or base block for the base of a free standing wall;
FIG. 19 is a perspective view of a half base block for a free standing wall;
FIG. 20 is a top plan view of a free standing retaining wall wherein the blocks are illustrated as having the shape of a right trapezoid in plan.